José Antonio Félix Ballesteros

Remote · Mexico City

• Own architecture and technical direction for AWS serverless prop-tech products, leading a tech team through design reviews, IaC, and GitLab CI/CD.
• Drove 5xx errors down ~80% (≈200 → ≈40/month) with end-to-end observability — Datadog dashboards, CloudWatch alarms, and AWS X-Ray distributed tracing across services.
• Shipped Stripe-metered subscriptions and free trials behind A/B-tested pricing flows, lifting monthly revenue up to 25%.

Remote · Mexico City

• Decomposed a Node.js/TypeScript monolith into 15+ serverless API stacks and 100+ Lambda functions spanning notifications, real-time experiences, and third-party integrations.
• Designed an API-as-a-Product layer: API-key auth, per-organization access control, and usage-metered billing (~31k billable external calls/month).
• Cut cold starts ~50% by trimming Lambda bundles from 6MB+ to <1MB through tree-shaking, dependency pruning, and bundler tuning.

Remote · Guadalajara

• Built features across a React loan-application platform and an Angular admin dashboard, backed by Node.js services over SQL.
• Integrated Veriff identity verification and remediated high-risk vulnerabilities — IDOR, access-control misconfigurations, and sensitive error disclosure.

Remote

• Built custom Shopify storefront sections in Liquid, JavaScript, and SCSS, wired into the Theme Editor for merchant-configurable layouts.
• Converted Figma designs into responsive, pixel-accurate themes, shipping approved design to live store in 1–3 days.